Merge pull request #4078 from sylvestre/update-i

{cp, mv} -i --update source existing should not do anything and exit 0

src/uu/cp/src/cp.rs

@@ -1264,6 +1264,12 @@ fn copy_file(
     symlinked_files: &mut HashSet<FileInformation>,
     source_in_command_line: bool,
 ) -> CopyResult<()> {
+    if options.update && options.overwrite == OverwriteMode::Interactive(ClobberMode::Standard) {
+        // `cp -i --update old new` when `new` exists doesn't copy anything
+        // and exit with 0
+        return Ok(());
+    }
+
     if file_or_link_exists(dest) {
         handle_existing_dest(source, dest, options, source_in_command_line)?;
     }

src/uu/mv/src/mv.rs

@@ -371,6 +371,12 @@ fn rename(from: &Path, to: &Path, b: &Behavior) -> io::Result<()> {
     let mut backup_path = None;
 
     if to.exists() {
+        if b.update && b.overwrite == OverwriteMode::Interactive {
+            // `mv -i --update old new` when `new` exists doesn't move anything
+            // and exit with 0
+            return Ok(());
+        }
+
         match b.overwrite {
             OverwriteMode::NoClobber => return Ok(()),
             OverwriteMode::Interactive => {

tests/by-util/test_cp.rs

@@ -215,6 +215,18 @@ fn test_cp_target_directory_is_file() {
         .stderr_contains(format!("'{}' is not a directory", TEST_HOW_ARE_YOU_SOURCE));
 }
 
+#[test]
+fn test_cp_arg_update_interactive() {
+    new_ucmd!()
+        .arg(TEST_HELLO_WORLD_SOURCE)
+        .arg(TEST_HOW_ARE_YOU_SOURCE)
+        .arg("-i")
+        .arg("--update")
+        .succeeds()
+        .no_stdout()
+        .no_stderr();
+}
+
 #[test]
 fn test_cp_arg_interactive() {
     let (at, mut ucmd) = at_and_ucmd!();

tests/by-util/test_mv.rs

@@ -184,6 +184,25 @@ fn test_mv_interactive() {
     assert!(at.file_exists(file_b));
 }
 
+#[test]
+fn test_mv_arg_update_interactive() {
+    let (at, mut ucmd) = at_and_ucmd!();
+
+    let file_a = "test_mv_replace_file_a";
+    let file_b = "test_mv_replace_file_b";
+
+    at.touch(file_a);
+    at.touch(file_b);
+
+    ucmd.arg(file_a)
+        .arg(file_b)
+        .arg("-i")
+        .arg("--update")
+        .succeeds()
+        .no_stdout()
+        .no_stderr();
+}
+
 #[test]
 fn test_mv_no_clobber() {
     let (at, mut ucmd) = at_and_ucmd!();